A gunman was shot and killed by police after he engaged in an hours-long standoff inside a Panera Bread restaurant in Princeton, New Jersey, across the street from the Princeton University campus, prosecutors said.

The incident began shortly after 10 a.m. when the armed man went into the restaurant; customers and employees fled while police secured the perimeter, the New Jersey Attorney General’s office said.

After several hours, negotiators were unable to get the suspect to surrender peacefully, the attorney general's office said.

Shortly before 3 p.m., the suspect was shot dead by police, the attorney general's office said.

It appears that no one was injured.

Though the restaurant is steps from the Ivy League campus, this week is Princeton's spring break, so classes are not in session, the university said.

Some neighboring buildings were shut down and two campus buildings near Panera were evacuated as a precaution, the school said.